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  #11  
Old 03-26-2018, 02:05 PM
smokyray's Avatar
smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,671
Default VNE...

Dave,
UR welcome sir.
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  #12  
Old 03-26-2018, 02:06 PM
dukekimbrough dukekimbrough is offline
 
Join Date: Sep 2009
Location: ft. worth, tx
Posts: 11
Default RV 4 left fuel tank

Looking for advice / videos of fuel tank build for RV249
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  #13  
Old 03-26-2018, 02:56 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 3,361
Default

Quote:
Originally Posted by gmcjetpilot View Post
....Dave Anders with his super fast RV-4 has been over 250 mph....
Dave Ander's RV-4 does not have the stock tail. I don't remember if he changed thicknesses, but he glued it as well as riveted it, and if I remember correctly, he has extra ribs in it. So his speed does not change whatever Vne margin there might be on a stock RV-4.

Dave
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  #14  
Old 03-26-2018, 03:31 PM
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smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,671
Default It's riveting...

Quote:
Originally Posted by David Paule View Post
Dave Ander's RV-4 does not have the stock tail. I don't remember if he changed thicknesses, but he glued it as well as riveted it, and if I remember correctly, he has extra ribs in it. So his speed does not change whatever Vne margin there might be on a stock RV-4.

Dave
Dave,
I've inspected Dave A's RV4 up close and spoken with him many times over the years. As David mentioned, his 4's elevators trailing edges are riveted, not bent. He also has wing extensions and carbon fiber parts and a counterbalanced rudder. Anything that sticks out in the breeze is faired. It's a clean machine through and through. His IO-360A1B6 (angle valve/counterbalanced crank) was custom built by LyCon and dynoed well North of 220HP mated to a WW constant speed composite prop. Dave's quote is on speed mods: "It's not one big thing but alot of little ones. "
https://www.youtube.com/watch?v=gCONImxbs7g

It smokes...

V/R
Smokey


PS: My HR2 had the stock RV4 tail with .020 elevator and rudder skins, no mods whatsoever.


Last edited by smokyray : 03-26-2018 at 03:38 PM.
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  #15  
Old 03-26-2018, 03:53 PM
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RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 687
Default

Quote:
Originally Posted by smokyray View Post
After the RV8 structural failure several years ago, Van's has been passionately neutral about VNE questions. Their calculations remain unchanged and I believe will for a long time to come.

Rob Ray
Livin the Dream...
But note that since then, Van's has redefined Vne (Redline) on all stock models (except maybe the RV-12) from Indicated Airspeed (IAS) to True Airspeed (TAS). Makes a difference at altitude. Unfortunately, Van's has not been very clear on this change (except for the RV-14).
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 280 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel H-201B Standard Libelle, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 03-26-2018 at 04:22 PM.
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  #16  
Old 03-27-2018, 08:15 AM
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smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,671
Default TRUE to form...

Carl,
Four score and many moons (14yrs) ago, (right after my RV4 flutter incident), Van and I exchanged emails. He queried me on my numbers and shared his thoughts on what actually happened. They were as you could figure, logical, well thought out and calculated.
In the split second I had to take a mental snapshot glance at all of my flea market purchased steam gauges in "The Bandit" when the incident occurred, Van had crunched some fairly accurate numbers on TAS VNE that I (and many other early RVers) hadn't considered. Potential litigation notwithstanding, I'm sure that is what they now publish as gospel.

Of course like all the other RV's, mine says "Experimental" on the canopy rail...
Your mileage may vary...

V/R
Smokey

PS: During the ensuing post-incident airframe inspection on "The Bandit", the only glitch I found was my elevator trim tab with 1/4" up and down play. I remedied this and in the next 500hrs never had a repeat although I never approached those TAS numbers again. .
Leaves one to wonder...

Last edited by smokyray : 03-27-2018 at 08:30 AM.
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  #17  
Old 03-27-2018, 09:00 AM
Michael Henning Michael Henning is offline
 
Join Date: Jun 2011
Location: Nashua, NH
Posts: 470
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Smoky,
Did he think it was flutter or a loose trim tab?
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Mike
RV-4 #2750
N654ML
IO-360
WW150C Prop
1018 lbs
Flying
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  #18  
Old 03-27-2018, 10:01 AM
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smokyray smokyray is offline
 
Join Date: Jan 2005
Location: TX32
Posts: 1,671
Default Flutter Bug...

Michael,
As we all know, Van is the Mr. Spock of the sport aircraft world. He speaks in analytical and logical terms and doesn't jump to conclusions or hypothesize unless backed up with facts.
In my case he didn't conclude as to the how but to the why.

In the end, Inconclusive.
V/R
Smokey

PS: I have my theories and have watched numerous flutter videos and spoken to several very smart Aeronautical Engineering qualified people including my good friend a former Van's engineer "KK".
We all believe that it was indeed flutter possibly accentuated by trim tab "buzz"....I may never know for sure.

Last edited by smokyray : 03-27-2018 at 10:04 AM.
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  #19  
Old 03-27-2018, 11:12 AM
RV8JD's Avatar
RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 687
Default

Quote:
Originally Posted by smokyray View Post
Carl,
Four score and many moons (14yrs) ago, (right after my RV4 flutter incident), Van and I exchanged emails. He queried me on my numbers and shared his thoughts on what actually happened. They were as you could figure, logical, well thought out and calculated.
In the split second I had to take a mental snapshot glance at all of my flea market purchased steam gauges in "The Bandit" when the incident occurred, Van had crunched some fairly accurate numbers on TAS VNE that I (and many other early RVers) hadn't considered. Potential litigation notwithstanding, I'm sure that is what they now publish as gospel.

Of course like all the other RV's, mine says "Experimental" on the canopy rail...
Your mileage may vary...

V/R
Smokey

PS: During the ensuing post-incident airframe inspection on "The Bandit", the only glitch I found was my elevator trim tab with 1/4" up and down play. I remedied this and in the next 500hrs never had a repeat although I never approached those TAS numbers again. .
Leaves one to wonder...
Understand.

At least for the RV-8, there appears to be a fair amount of structural and flutter margin with the Vne set to 230 MPH TAS. See my post:

http://www.vansairforce.com/communit...3&postcount=86
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 280 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel H-201B Standard Libelle, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 03-27-2018 at 11:15 AM.
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  #20  
Old 03-27-2018, 11:33 AM
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skylor skylor is offline
 
Join Date: Aug 2009
Location: Southern California
Posts: 596
Default

Quote:
Originally Posted by RV8JD View Post
Understand.

At least for the RV-8, there appears to be a fair amount of structural and flutter margin with the Vne set to 230 MPH TAS. See my post:

http://www.vansairforce.com/communit...3&postcount=86
Just because someone once got away with speeds well above VNE without flutter and destruction does not necessarily mean there is a "fair amount of structural and flutter margin." It just may mean that that particular aircraft on that particular day didn't experience the stimulus needed to initiate flutter, particularly if control tap tests were not conducted at those speeds...

Skylor
RV-8

Last edited by skylor : 03-27-2018 at 11:51 AM.
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